Front view of the Sony SRS XB21 speaker with its lights glowing.

How to Check Sony SRS XB21 Battery

Covers how to check battery in the Sony SRS XB21 wireless Bluetooth speaker, and also, how to tell if the battery life is fading over time.

How to Check Sony SRS XB21 Battery, Current Charge

1. First, Turn ON the XB21

You won’t be able to read battery charge status unless the speaker is ON.

The -Power- button on the Sony SRS XB21 speaker.
Sony SRS XB21 -Power- button.

To turn on the unit, press and release the Power button, pointed at by the aqua arrow in the last picture. It’s on the speaker top, and the right most button in the button panel as you face the front of this Sony Bluetooth speaker.

The Power lamp, also on the top panel, should then light up. E.g. See this in the next picture. Then the speaker may make a two-beep sound if it connects to a close-by device.  If it does not turn on, then the battery could be completely dead.

The glowing -Power- light.
The -Power- lamp glowing.

But as long as there’s some energy in the battery, the speaker should power up.  When it does, move on to the next step.

2. Look at the CHARGE Lamp on the XB21

You can tell at a quick look if the battery is tottering on the edge of going dead by way of the CHARGE lamp. When the battery is not extremely low, this lamp is dark. But when the speaker has just a tiny charge left, the CHARGE lamp flashes orange.

E,g, The next picture shows the CHARGE lamp location.  It’s in the port compartment in the rear of the speaker, near the right side, very close to the USB input port.

Picture of the -CHARGE- light glowing.
The -CHARGE- lamp glowing.

How to Check Sony SRS XB21 Battery, Overall Charge Capacity

When the speaker is new, and using a micro USB charger, the battery charge time is about four and a half (4.5) hours to reach a full charge. And, the full battery should last for around twelve (12) hours of play time before dying, when you run it at low to medium volume levels and with surrounding temperatures in the 70s or 80s.  At maximum volume, you might only get a few hours of play.

But a sign of a faulty battery, is that it runs out of power too soon. Or it takes too little or too much time to fully charge. So if you fully recharge your 21, but it repeatedly plays for under twelve hours at low volumes before shutting OFF, then its battery may be bad, and unable to hold a full charge anymore.  This is common of aging lithium ion batteries of the type they put into this unit.

Picture of the dark -CHARGE- light.
The dark -CHARGE- lamp.

Or if the CHARGE light goes out in under two hours after you start replenishing the speaker from dead state, then the battery may also be failing.

Also, if the SRS XB21 battery takes longer than six hours to finish filling up, this could also mean a battery nearing its end of service life.  It might mean too, that the charger you have is not hefty enough to recharge the speaker in the 4.5 hours that speakers like this one require.  So to eliminate this chance, try another charger.

Finally, slow charging can occur because your USB charging cable is too thin.  So for best results, we suggest using a thick micro USB cable (one that easily carries 2 amps).

Other Posts About the Sony SRS XB21 Speaker

    1. How to Charge Sony SRS XB21 Bluetooth Speaker
    2. Sony SRS XB21 Charge Time for Fastest Recharge
    3. Pairing Bluetooth Help for the Sony SRS XB21 BT Speaker
    4. Sony SRS XB21 Charger Type and Replacement
    5. How Sony SRS XB21 Not Charging, How to Repair

Related Posts to How to Check Sony SRS XB21 Battery

    1. Testing the Sony SRS XB20 Battery
    2. How to Check Sony SRS XB13 Battery
    3. Checking Battery Status on the Sony SRS XB12 Speaker
    4. How to Test the Sony SRS XB10 Speaker Battery
    5. How to Check Sony SRS XB01 Battery

References for How to Check Sony SRS XB21 Battery

    1. Sony SRS XB21 Product Page at

Change History

    • 2022-08-18: First published.